Jordan had promised to begin executing Islamic extremists on death row in response to the murder of Maaz al-Kassasbeh, who was captured by IS when his plane went down in Syria in December.

Jordan's King Abdullah II cut short a visit to Washington after a gruesome video of the airman's killing emerged, describing Kassasbeh as a hero and vowing to take the battle to IS.

Egypt-based Al-Azhar, Sunni Islam's most prestigious seat of learning, called for the "killing, crucifixion and chopping of the limbs of Islamic State terrorists" after the airman's murder.

Rishawi, 44, was sentenced to death for her participation in triple hotel bombings in Amman in 2005 that killed 60 people.

Advertisement

IS had offered to spare Kassasbeh's life and free Japanese journalist Kenji Goto -- who was later beheaded -- if she were released.

Jordan had on Tuesday vowed to avenge the killing of Kassasbeh, hours after the harrowing video emerged online purporting to show the caged 26-year-old F-16 fighter pilot engulfed in flames.

The video -- the most brutal yet in a series of recorded killings of hostages by IS -- prompted global revulsion and vows of unwavering international efforts to combat the Sunni Muslim extremist group.

The killing sparked outrage in Jordan and demonstrations in Amman and the city of Karak, the home of Kassasbeh's influential tribe.

The executions came just weeks after Jordan ended an eight-year moratorium on the death penalty, drawing criticism from human rights groups.

Rishawi was closely linked to IS's predecessor organisation in Iraq and seen as an important symbol for the jihadists.

Karboli was sentenced to death in 2007 on terrorism charges, including the killing of a Jordanian in Iraq.

Jordan, a crucial ally of Washington in the Middle East, is one of several Arab countries that have joined a US-led coalition of countries carrying out air strikes against IS in Syria and Iraq.

The New York Times, quoting US officials, reported Wednesday that the United Arab Emirates had suspended its participation in December after Kassasbeh's capture due to fears for the safety of its pilots.

There was no official confirmation of the report.

Jordan promised to avenge the pilot's murder, with government spokesman Mohammad al-Momani saying: "Jordan's response will be earth-shattering".

US President Barack Obama, who hosted King Abdullah in a hastily organised Oval Office meeting, led international condemnation of the murder, decrying the "cowardice and depravity" of IS.

He said the brutal killing would only strengthen international resolve to defeat the extremists.

British Prime Minister David Cameron, who has sent warplanes to join the US-led strikes against IS in Iraq, denounced "the sickening murder".

"We will not stop until these evil extremists and their poisonous ideology are defeated," he added.

Kassasbeh was captured in December when his jet crashed over northern Syria on a mission that was part of the coalition air campaign against the jihadists.

Jordanian state television suggested he was killed on January 3, before IS offered to spare his life and free Goto in return for Rishawi's release.

The highly choreographed 22-minute video released Tuesday shows Kassasbeh at a table recounting coalition operations against IS, with flags from the various Western and Arab countries in the alliance projected in the background.

It then shows Kassasbeh dressed in an orange jumpsuit and surrounded by armed and masked IS fighters in camouflage.

It cuts to him standing inside a cage and apparently soaked in petrol before a masked jihadist lights a trail of flame that runs to the cage and burns him alive.

Saudi Arabia, the spiritual home of Islam and another member of the coalition, condemned the "misguided ideology" behind Kassasbeh's killing and accused groups like IS of seeking "to distort the values of Islam".

The UAE said the actions of IS "represent epidemics that must be eradicated by civilised societies without delay".

Iran condemned the "inhuman and un-Islamic act".

IS had previously beheaded two US journalists, an American aid worker and two British aid workers in similar videos.

Shiraz Maher, from the International Centre for the Study of Radicalisation at King's College, London, described the latest footage as "simply the most horrific, disgusting thing I have seen from Islamic State in the last two years".

IS has seized swathes of territory in Syria and Iraq and last year declared a "caliphate" in areas under its control, imposing its brutal interpretation of Islam and committing widespread atrocities.

Kassasbeh was the first coalition serviceman captured since it launched strikes against IS last year.

The Jordan Times said in an editorial that the country would rally against the "ruthless" murder of the pilot "who is now the son of all Jordanians".